Turn raw command-line text into useful, repeatable results with two of Linux's most capable text-processing tools. This hands-on course develops a practical mental model for sed as a stream editor and awk as a field-oriented processing language, so you can choose the right tool instead of assembling fragile one-off commands.
You will work with sample text, CSV-style data, /etc/passwd, and web server logs. Short guided exercises build toward a system-report challenge in which you clean log records, extract HTTP status codes, count 404 responses, calculate an error rate, and produce a concise report.
What You Will Learn
- Replace the first or every matching value with
sedsubstitution commands - Choose readable substitution delimiters and edit files in place with a backup
- Delete, insert, and selectively print lines with
sedaddresses and commands - Extract fields with
awk, including custom separators and the final field via$NF - Filter records with numeric conditions or text patterns and label output with
NR - Structure
awkprocessing withBEGIN, per-record logic, variables, andEND - Sum values, count conditional matches, calculate percentages, and format a report
Who This Course Is For
This intermediate course is for Linux users, system administrators, DevOps learners, and developers who want to inspect and transform structured text without writing a larger program. It is especially useful if you regularly handle logs, command output, delimited files, or simple operational reports.
Prerequisites: Basic familiarity with the Linux terminal, files and directories, pipes, and output redirection. Prior sed or awk experience is not required.
Learning environment: A LabEx Linux terminal with prepared text, account, CSV-style, and web-log data files.
Frequently Asked Questions
When should I use sed, and when should I use awk?
Use sed when the task centers on changing, deleting, inserting, or selecting lines in a text stream. Use awk when you need to split records into fields, apply conditions, maintain counters or totals, and assemble a report. The final challenge uses both in sequence.
Will the exercises modify real system data?
No. The course reads /etc/passwd to practice field extraction, but does not change it. Editing exercises use prepared project files, and the substitution lab shows both preview-only output and sed -i.bak, which preserves an original backup.
What will I produce in the final challenge?
You will turn a quoted sample web-server log into several verifiable artifacts: a cleaned log, a status-code list, a 404 count, an error-rate file, and a one-line summary such as Total: 8, 404: 2, Rate: 25%.
